But the two last-year engineering majors at George Mason University, in Fairfax, Virginia, appear to have invented a way to use sound waves to put out fires. It started as an idea for a research project, and after a year of trial and error and spending about $600 of their own money, they have built a somewhat portable sound generator, amplifier, power source and focusing tube that would seem to have great potential in attacking fires in a variety of situations.
Robertson, 23, and Tran, 28, applied for a provisional patent at the end of November, which gives them a year to do further testing on other flammable chemicals – so far they have put out only fires started with rubbing alcohol – and to continue to refine their device. Although they originally conceived of the device as a way to put out kitchen fires and, perhaps, fires in spacecraft, a local fire department already has asked them to test their bass waves on a structure fire; they think the concept could replace the toxic chemicals involved in fire extinguishers.
But how does it work? The basic concept, Tran said, is that sound waves are also “pressure waves, and they displace some of the oxygen” as they travel through the air. Oxygen, we all recall from high school chemistry, fuels fire. At a certain frequency, the sound waves “separate the oxygen from the fuel. The pressure wave is going back and forth, and that agitates where the air is. That specific space is enough to keep the fire from reigniting.”"
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